Lewis ‘Scooter’ Libby, pardoned in 2018

The former chief of staff to Vice-President Dick Cheney was convicted of perjury and obstruction for lying about his conversations with reporters about the outed CIA operative Valerie Plame. President George W Bush commuted his 30-month prison term but not his $250,000 fine. According to the New York Times, Bush and Cheney spent their final hours in office arguing over whether Libby should receive a pardon; Bush refused to grant one. Donald Trump pardoned him in 2018, saying: “I don’t know Mr Libby but for years I have heard that he has been treated unfairly.”

Richard Nixon, pardoned in 1974

President Richard Nixon was pardoned by his successor, Gerald Ford, after the Watergate scandal. Photograph: Mondadori/Mondadori via Getty Images

In the wake of the Watergate scandal, Nixon became the only US president in history to resign. His successor, Gerald Ford, had barely been in office for a month when he decided to pardon Nixon to avoid a protracted legal process. But, the New York Times reported: “At the White House, switchboard operators said, ‘angry calls, heavy and constant’, began jamming their boards soon after Mr Ford’s announcement.”

Ford said in a 1984 interview: “The political fallout was far more serious than I contemplated.”

Joe Arpaio, pardoned in 2017

Trump’s first use of the president’s pardon power came after seven months in the job, when he pardoned the former sheriff Joe Arpaio, the hardline Arizona lawman who was convicted of contempt of court in July for defying a judge’s order to stop racially profiling Latinos. During Arpaio’s 24-year tenure as sheriff of Maricopa county, he gained notoriety for detaining hundreds of undocumented immigrants in a Tent City jail and forcing them to wear pink underwear. The sheriff courted controversy and media attention as he became a national figurehead for the virulent xenophobia Trump embraced in his presidential campaign.

Caspar Weinberger, pardoned in 1992

The former US secretary of defense Caspar Weinberger in 2001. Photograph: Ed Wray/AP

The former defence secretary was the most senior member of Ronald Reagan’s cabinet indicted for perjury and obstruction of justice during the Iran-Contra affair. The charges arose from his testimony that he did not know about the illegal sale of arms to Iran and anti-government guerrillas in Nicaragua; his private notes later revealed this was untrue. President George HW Bush defied congressional opposition to grant Weinberger an executive pardon days before the case came to trial.

Marc Rich, pardoned in 2001

The financier Marc Rich was pardoned by Bill Clinton. Photograph: AP

The commodities trader fled to Switzerland in 1983, accused of evading $48m in taxes and illegally trading with Iran in oil. But Rich, whose ex-wife was a prominent fundraiser for the Democrats, was pardoned by Bill Clinton on his last day as US president in what a New York Times editorial called “a shocking abuse of presidential power and a reminder of why George W Bush’s vow to restore integrity to the Oval Office resonates with millions of Americans”.

Chelsea Manning, sentence commuted in 2017

Former US soldier Chelsea Manning, after her release from prison. Photograph: HO/AFP/Getty Images